An industrial robot such as an arm-type robot is designed to work interlocking with external devices controlling the posture and the like of a work piece to be worked. When there is a possibility that a worker will approach these external devices, the worker makes a decision to cut the power supplies to the external devices so as to secure the worker's safety.
In addition, in some systems, a robot and a plurality of external devices such as external axis devices are divided into desired groups, and means for on/off controlling power supplies is provided in a controller for each divided control group, so that the safety of a worker can be secured simply. (For example, see Japanese Patent Publication No. JP-A-11-90880/(1999))
However, in the aforementioned method in which the power supplies are turned on/off in accordance with the user's decision, there is no means for securing the safety when the worker operates in error. On the other hand, in the method in which the means for on/off controlling the power supplies is provided in the controller for each divided control group, there has been a problem that the method is inconvenient because it cannot follow the change or the like of the work sequence of the worker.
Patent Document 1: Japanese Patent Laid-Open No. 90880/1999